The present invention relates to the down sampling of a signal issued from an asynchronous sensor especially for the inputting of the down sampled signal into a retinal prosthesis/a retina implant.
The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section. Furthermore, all embodiments are not necessarily intended to solve all or even any of the problems brought forward in this section.
Retinal prostheses hold the promise to partially restore visual functionality in subjects affected by retinal degenerative diseases.
However, state of the art implants only comprise a few hundreds pixels. Increasing the pixel density in implants is a very challenging process, and alternative techniques need to be exploited to compensate for reduced spatial resolution of said implants.
On the other hand, retina sensors (or asynchronous light sensors) may comprise thousands of pixels. Neuromorphic vision sensors (i.e. retina sensors/asynchronous sensors) asynchronously deliver streams of visual information with high time resolution, without the need to wait for a frame to be ready.
Sampling a scene to a lower resolution than the one captured by the retina sensors (cameras) is therefore a possible processing step.
The usual way to implement a down sampling (i.e. sampling a scene to a lower resolution) is to use the standard computer vision techniques that may be used with standard images/frames, etc.
However standard computer vision techniques (which handle frames) might not be the most adequate solution to deliver useful information to implanted patients. Indeed asynchronous information received from the retina sensors then need to be converted into 2D standard frames so that the usual method for down sampling may be used: this conversion may be processor consuming and time information may be lost.
There is thus a need for a method for down sampling a signal issued from asynchronous sensors without converting the signal into 2D (i.e. working directly in the asynchronous domain).